Musladin-Lueke Syndrome

Musladin-Lueke Syndrome (MLS) is a disorder affecting the development and structure of connective tissue that is characterized by stiff joints, an abnormal facial expression, and thick, tight skin.

Found in

1 in 830 dogs

in our testing

Key Signs

Thick tight skin, Stiff joints, Broad skull, Slanted eyes

Age of Onset

At birth

Present at birth


Autosomal Recessive

For autosomal recessive disorders, dogs with two copies of the variant are at risk of developing the condition. Dogs with one copy of the variant are considered carriers and are usually not at risk of developing the disorder. However, carriers of some complex variants grouped in this category may be associated with a low risk of developing the disorder. Individuals with one or two copies may pass the disorder-associated variant to their puppies if bred.

Likelihood of the Condition

High likelihood

At risk dogs are highly likely to show signs of this disease in their lifetime.

What to Do

Here’s how to care for a dog with MLS

Partner with your veterinarian to make a plan regarding your dog’s well-being, including any insights provided through genetic testing. If your pet is at risk or is showing signs of this disorder, then the first step is to speak with your veterinarian.

For Veterinarians

Here’s what a vet needs to know about MLS

Clinical signs of this disorder are present from birth. Affected dogs are smaller in size than their littermates. Affected dogs also have a broad skull, wide-set slanted eyes, and skin that appears thick and tight. The disorder is characterized by extremely limited joint mobility and short digits that causes the dogs to walk upright, often on their tip-toes. Other characteristics of the disorder include a high-pitched bark and an exceptionally exuberant temperament. Dogs with MLS typically have a normal life span, but commonly develop painful arthritis. The clinical signs usually stabilize by 1 year of age.

Treatment is pain management, supportive care, and symptomatic depending on the severity of the dog's clinical signs.

For Breeders

Planning to breed a dog with this genetic variant?

There are many responsibilities to consider when breeding dogs. Regardless of test results it is important that your dog is in good general health and that you are in a position to care for the puppies if new responsible owners are not found. For first time or novice breeders, advice can be found at most kennel club websites.

This disease is autosomal recessive meaning that two copies of the mutation are needed for disease signs to occur. A carrier dog with one copy of the MLS mutation can be safely bred with a clear dog with no copies of the MLS mutation. About half of the puppies will have one copy (carriers) and half will have no copies of the MLS mutation. Puppies in a litter which is expected to contain carriers should be tested prior to breeding. Carrier to carrier matings are not advised as the resulting litter may contain affected puppies. Please note: It is possible that disease signs similar to the ones caused by the MLS mutation could develop due to a different genetic or clinical cause.

Technical Details

Variant C>T
Chromosome 9
Coordinate 49,931,561

All coordinates reference CanFam3.1

References & Credit

Credit to our scientific colleagues:

Bader, H. L., Ruhe, A. L., Wang, L. W., Wong, A. K., Walsh, K. F., Packer, R. A., … Neff, M. W. (2010). An ADAMTSL2 founder mutation causes Musladin-Lueke syndrome, a heritable disorder of Beagle dogs, featuring stiff skin and joint contractures. PLoS ONE, 5(9), 1–8. View the article